The owner's manual for my 2000 BMW 328i says in the interests of safety and handling, I should NOT rotate my tires. And it implies that tire rotation will not extend the life of the tires in a meaningful way. But the instructions with my new tires (not to mention those from the tire reseller and the mechanic who services my car) all suggest periodic rotation. To rotate, or not to rotate? -- Larry

TOM: This was one of the great civic debates of the 20th century, Larry.

RAY: Make that 20th AND 21st.

TOM: We've always felt that tire rotation is of marginal value in terms of saving you money. Why? Because the cost of tire rotation roughly equals the amount you'd save by extending your tire life.

RAY: You can see why mechanics like it. Not only is it an easy few bucks for us, but it also gets your car into the shop again so we can sell you other services -- like engine flushes and fuzzy-dice reupholstering!

TOM: So, our feeling has always been that if the tire rotation is free, do it. In other words, if you're having your brakes checked, and the wheels are already off the car and your mechanic is nice enough to put them back on different wheels for nothing, then do it. That's what we do for our customers.

RAY: Actually, we just get confused, and don't remember where the wheels came from. So we tell our customers, "We THINK we rotated your tires."

TOM: But if you have to pay for tire rotation as a separate service, it's pretty much a wash, as far as we can tell.

RAY: As for BMW, it figures that anyone who buys a BMW places handling above a few bucks. And in many cases, its cars come with directional tires, which are only supposed to be rotated front to back. When you rotate that way, you're supposed to do it every 3,000 miles, which further reduces any economic advantage.

TOM: BMW cites safety because the front and rear tires develop different wear patterns. And for at least a little while -- until the wear evens out, which is the point of tire rotation -- you might have slightly inferior handling with newly rotated tires.

RAY: It's a technicality, and very few drivers would ever notice it, but BMW is, technically, correct.

TOM: Still, we see nothing wrong with rotating your tires. No harm will be done, in our opinion. But if you're paying your BMW mechanic $125 an hour to move your tires around (and eight bucks a wheel for rebalancing, too), it's very unlikely you'll save any money in the long run, Larry.